Arrangement with a rotary slide



1, 1956 F. LEHNER 2,759,464

RRANGEMENT WITH A ROTARY SLIDE Filed May 19, 1953 2 Sheets-Sheet 1 Jig.1

United States Patent ARRANGEMENT WITH A ROTARY SLIDE Felix Lelmer,Hallein, Austria, assignor to Hans List, Graz, Austria Application May19, 1953, Serial No. 355,907

Claims priority, application Austria May 19, 1952 1 Claim. (Cl. 123-59)The invention relates to a rotary slide, particularly for controllingthe exhaust in two-stroke internal-combustion engines.

The known rotary slides for internal-combustion engines with severalcylinders are constructed either undivided or divided with respect tothe bearings and therefore the assembly and replacement is verydifiicult, because larger engine parts, such as the slide casing are tobe removed. Or, a large free space is necessary in axial direction whichspace, however, is often not available on ships. In undividedconstructions, it is, moreover, of disadvantage that the same cannot bestandardized for motors with different numbers of cylinders. In theinterest of an easy and simple production it is, however, desirable forfactories which simultaneously produce motors with like cylinderelements and different numbers of cylinders to manufacture as many likeparts as possible.

The rotary slides divided in the bearings are expen' sive and require avery high precision in the manufacture According to the invention theabove disadvantages are avoided by providing a rotary slide comprising aseparate controlling or regulating part for each motor cylinder in aslide casing open on one side, the ends of which controlling part arefastened at the sides of two shaft stubs, the sides of which are remotefrom the sliding surface of the controlling part. In this arrangementthe axial extent of the sliding surface of the controlling part issmaller than the distance between the stub shafts. It is therebypossible to mount or remove the rotary slide to and from the casingalready after removing the exhaust head. Furthermore, thestandardization of the relatively inexpensive and simple elements of therotary slide for motor types with dilferent numbers of cylinders will bepossible.

In engines with cylinders arranged in line the individual controllingparts can also be arranged one behind the other by adjusting commonshaft stubs for each two adjacent joints. The so formed unit of therotary slide is driven by the crank shaft in usual manner withunchangeable ratio of revolutions.

According to a further feature of the invention it is advantageous tofasten the controlling parts by applying sleeves by means of radiallyarranged screws. Furthermore, the individual controlling parts arefitted with balancing masses at the sides opposite to their slidingsurface for balancing the controlling slide or the engine. Each of theshaft stubs is advantageously supported in a pipe piece, for example inhallor roller-bearings and the pipe pieces are axially adjusted in acommon bore in an undivided rotary slide casing.

In the following the invention is illustrated by way of example.

Fig. 1 shows a part of a two-stroke internal-combustion engine, viz. acylinder in middle-section and the rotary slide casing in section alongthe line I-I of Fig. 2.

Fig. 2 shows a section through the rotary slide casing along the lineII-II of Fig. 1.

In the motor casing 1 a cylinder liner 2 is mounted which is fastened atthe cylinder head 3 by means of screws not illustrated. The cylinderhead 3 is fastened by means of screws on the motor casing 1. The inletslots 4 and outlet slots 5 are controlled by means of a piston 6. Thechannel for the supply of air or the fuelair-mixture to the inlet slots4 are not illustrated in Fig. 1. A channel 7 leads from the outlet slots5 over the open undivided casing of the exhaust rotary slide 8 to theexhaust head 9. The exhaust pipe is connected to the pipe piece 24. Theexhaust head is cooled with water, the water inlet is designated by 27,the water outlet is not illustrated. In the rotary slide casing 8 isarranged the rotary slide for rotation in the direction of the arrow,which slide consists of two controlling parts 10 and the shaft stubs 11,12 and 13. The controlling parts 10 are secured against rotation bymeans of claws 17 at that side of the shaft stub which is remote fromthe sliding surface 14 of the controlling parts 10. The fastening iscarried out by using fitting sleeves 15 by means of radially arrangedscrews 16. The claws 17 are formed reinforced for the sake of balancingmasses.

The shaft stubs 11 to 13 are arranged in roller bearings 21 to 23located in pipe pieces 18, 19, 20 which are axially introduced into thecasing 8. The pipe pieces 18, 19, 20 having the same outer diameter areinserted into a common bore 26 of the undivided casing 8. The shaft stub11 serves as a bearing support but both controlling parts 10 are alsoconnected with one another by means of the shaft stub 12 secured againstrotation. The shaft stub 13 is provided with a driving wheel 25 for thewhole rotary slide.

In assembling the arrangement the pipe pieces 18, 19 and 20 are axiallylocated in the casing 8 together with shaft stubs 11, 12, 13 positionedin said pipe pieces, whereupon the controlling parts 10 are radiallyintroduced individually from outside and there fastened. In order toenable such an assembly the axial extent of the sliding surface 14 issomewhat smaller than the distance of the shaft stubs. For mounting andremoving the rotary slide only the exhaust head 9 is to be removed.

What I claim is:

In a two-stroke combustion engine the combination comprising a mainmotor casing, a plurality of cylinders in the main casing and arrangedin a row and having air inlet ports and outlet ports, a piston in eachcylinder and controlling the ports, a valve casing open at a side andthereat connected to the main casing and communicating with the outletports, rotary exhaust valve members for opening and closing thecommunication between the casing and the outlet ports and each includinga control part carrying an arcuate closure element and also includingstub shaft means each secured at its side remote from the closureelement to one end of a control part, the axial length of each closureelement being shorter than the distance between the ends of the stubshafts secured to the control part, the valve casing having an outeropening remote from the main casing and larger than the largestdimension of the control parts to permit the insertion thereof radiallyof the stub shafts.

References Cited in the file of this patent UNITED STATES PATENTS1,774,881 Fry Sept. 2, 1930 1,776,665 Riehm Sept. 23, 1930 1,887,661Pielstick Nov. 15, 1932 2,076,976 Burn Apr. 13, 1937

